A mass spectrometry analysis device for in-situ gas-solid phase photocatalytic reaction

Abstract

The present invention relates to a mass spectrometry analysis device for in-situ gas-solid phase photocatalytic reaction, and relates to the technical field of mass spectrometry analysis. It includes a photoionization time-of-flight mass spectrometry device and an in-situ photocatalytic reactor, which are connected by a differential chamber. The in-situ photocatalytic reactor includes a catalyst placement mechanism, a reaction light source, an inlet pipe and an outlet pipe; the improved catalyst placement mechanism includes a flat fixed bed and a hollow closed plate-shaped housing, both of which are made of quartz material; the reaction light source is located above the plate-shaped housing, and the light-emitting surface corresponds to the working surface of the fixed bed; one side edge of the plate-shaped housing is connected to the inlet pipe, and the other side edge is connected to the outlet pipe, and a sand core is provided in the outlet pipe. The present invention realizes more in-situ sampling of gas-phase intermediates, ultra-fast capture, is more conducive to the desorption of gas-phase intermediates under low pressure, and the molecular beam can "cool" gas-phase molecules, which is very suitable for studying the reaction mechanism of gas-phase intermediates through gas-solid phase photocatalytic reaction, and then guiding the synthesis of catalysts.

Description

Technical Field

[0001] The present invention relates to the technical field of mass spectrometry analysis, and particularly relates to a mass spectrometry analysis device for in-situ gas-solid phase photocatalytic reaction. Background Art

[0002] Since 1967, when Professor Akira Fujishima discovered the phenomenon of photocatalysis in an accidental experiment, photocatalysis has attracted extensive attention. The basic principle of the photocatalytic reaction is that the photocatalyst generates electrons and holes under the excitation of light, and the generated electron-hole pairs will initiate the photocatalytic reaction. There are several typical applications of the gas-solid phase photocatalytic reaction: 1. With the development of industrialization and economy, more and more industrial waste gases (such as HCHO, H2S, SO2, CS2, NOx, etc.) are discharged into the atmospheric environment, and photocatalysis can utilize the sufficient light source in the environment to degrade these volatile harmful gases. 2. In September 2020, China clearly put forward the goals of "carbon peak" in 2030 and "carbon neutrality" in 2060, namely "dual carbon". The photocatalytic reduction of CO2 to high-value chemical products is a very important task, which can not only eliminate the excess CO2 gas in the environment, but also convert the inexhaustible solar energy into chemical energy. 3. Hydrogen energy is regarded as the clean energy with the greatest development potential in the 21st century, and the photocatalytic decomposition of water or other hydrogen storage compounds to produce hydrogen is also an important research field. 4. Natural gas, combustible ice, biogas, and shale gas contain a large amount of methane. Converting methane into more valuable chemical products is an important research field in contemporary catalytic conversion. Photocatalytic methane conversion can prevent excessive conversion of methane at a lower temperature and is currently a very promising technical field.

[0003] Currently, the characterization of photocatalytic reactions mainly focuses on the characterization of the catalyst itself. For example, transmission electron microscopy (TEM) and scanning tunneling microscopy (STM) can characterize the morphology of the catalyst, X-ray absorption fine structure spectroscopy (EXAFS) and X-ray diffraction (XRD) can characterize the crystal structure of the catalyst, and X-ray photoelectron spectroscopy can measure the composition and chemical state of the catalyst. Diffuse reflectance infrared spectroscopy, Raman spectroscopy, and electron paramagnetic resonance can in-situ characterize the adsorbed species on the catalyst surface. In particular, infrared spectroscopy and Raman spectroscopy assign some functional groups through vibration peaks, and very few intermediates and products can be accurately identified.

[0004] At present, mass spectrometry is a tool mainly used to characterize the gas phase products of gas-solid phase catalytic reactions, in addition to infrared spectroscopy and laser induced fluorescence. Since the recombination rate of photogenerated electrons and holes on the catalyst surface is fast and the conversion efficiency of reactants is low in photocatalytic reactions, photocatalytic reactions are generally kettle reactions. Regular extraction of gas from the reactor and offline qualitative and quantitative analysis on gas chromatography-mass spectrometry (GC-MS) are the most common analytical methods for stable gas phase products of photocatalysis. Through precise control of the catalyst, certain gas-solid phase photocatalytic reactions can also achieve higher reaction rates. Such reactions can also be used in fixed bed catalytic reactors, and the tail gas can be continuously monitored by GCMS. The problems of analyzing the gas phase components of gas-solid photocatalytic reactions by traditional GCMS are: 1. Sampling is not in situ and is under atmospheric pressure, so it is impossible to obtain information on unstable reaction intermediates in the gas phase; 2. Gas phase components are generally separated by gas chromatography and then analyzed by mass spectrometry. The gas chromatography separation time is as long as tens of minutes, making it difficult to capture unstable intermediates. However, if there is no gas chromatography, the tail gas enters the mass spectrometer directly, generally through 70eV electron bombardment ionization, the parent information is missing, the fragments interfere with each other, and it is impossible to clearly analyze the complex gas phase components in the gas-solid photocatalytic reaction; 3. Quadrupole mass spectrometry is mostly used in commercial GCMS. Quadrupole mass spectrometers have mass discrimination against gas phase ions with a mass-to-charge ratio below 50, and have low detection efficiency, which is very unfavorable for the detection of gas phase small molecules with a mass number below 50 in gas-solid photocatalytic reactions.

[0005] In situ molecular beam sampling-photoionization time-of-flight mass spectrometry can solve the detection problems of the above-mentioned commercial GCMS instruments, and has been verified in the capture of gas-phase reaction intermediates in reactions such as thermal catalytic synthesis gas to olefins, methanol to olefins, and methane oxidative coupling. However, the mass spectrometry capture of gaseous intermediates in in-situ photocatalytic reactions is still a major challenge, specifically facing the following problems: 1. Based on the design of an in-situ thermal catalytic reactor, the catalyst can be placed in a cylindrical quartz tube with an inner diameter of 6-10 mm, and the heating sleeve is replaced with a photocatalytic reaction light source. The gas-solid phase photocatalytic reaction is initiated by irradiating the catalyst in the cylindrical quartz tube. However, the problems with this structure are that, first, the photon irradiation area is limited, and second, there is a serious light scattering problem when irradiating the curved surface of the cylindrical quartz tube. Furthermore, photons cannot penetrate the curved surface of the quartz tube column to reach the inside of the solid catalyst, and a large amount of catalyst cannot function; 2. Although the traditional photocatalytic reactor has a large area for photocatalytic reaction, it still takes a long time of continuous irradiation to drive the reaction to continue under a normal pressure sealed environment through the adsorption equilibrium of the reaction gas on the catalyst surface. When the reaction gas can only flow around the catalyst and cannot fully contact the catalyst, the efficiency of the online photocatalytic reaction is very low in this case; 3. In addition, due to the too fast recombination of photogenerated electrons and holes on the catalyst surface of the photocatalytic reaction, the efficiency of the photocatalytic reaction itself is also much lower than that of thermal catalysis. Summary of the invention

[0006] In order to solve the problems existing in the mass spectrometry capture of gas-phase intermediates in the conventional in-situ mass spectrometry detection of gas-solid phase photocatalytic reactions, such as a large amount of catalyst being unable to function and low photocatalytic reaction efficiency, the present invention provides a mass spectrometry analysis device for in-situ gas-solid phase photocatalytic reactions.

[0007] The present invention connects an in-situ photocatalytic reactor and a photoionization time-of-flight mass spectrometer through a differential chamber, and the differential chamber can introduce gas-phase molecules in the photocatalytic reactor into the ionization chamber of the photoionization time-of-flight mass spectrometer in the form of a molecular beam at an ultra-fast speed.

[0008] A mass spectrometry analysis device for in-situ gas-solid phase photocatalytic reactions includes a photoionization time-of-flight mass spectrometry device and an in-situ photocatalytic reactor, which are connected by a differential chamber 9; the photoionization time-of-flight mass spectrometry device is a reflectron time-of-flight mass spectrometry analysis device; the in-situ photocatalytic reactor includes a catalyst placement mechanism, a reaction light source 5, an inlet pipe, and an outlet pipe; the improvement lies in:

[0009] The catalyst placement mechanism includes a flat fixed bed 6 and a hollow closed plate-shaped housing. The material of the fixed bed 6 is quartz, and the fixed bed 6 is located inside the plate-shaped housing. The material of the plate-shaped housing is quartz glass; the material of the fixed bed 6 is quartz, and the side of the fixed bed 6 where the catalyst is placed is the working surface; the reaction light source 5 is located above the plate-shaped housing, and the light-emitting surface of the reaction light source 5 corresponds to the working surface of the fixed bed 6; one end of the inlet pipe communicates with the middle of one side edge in the length direction of the plate-shaped housing, and a first valve 4 is provided on the inlet pipe adjacent to the fixed bed 6; one end of the outlet pipe communicates with the middle of the other side edge in the length direction of the plate-shaped housing, and a second valve 8 is provided on the outlet pipe adjacent to the fixed bed 6; the other end of the outlet pipe is located inside the differential chamber 9, and a sintered filter 11 is provided in the outlet pipe between the plate-shaped housing and the second valve 8;

[0010] During operation, the vacuum degrees in the plate-shaped housing and the differential chamber 9 are the same, ranging from 0.1 Torr to atmospheric pressure;

[0011] In the continuous injection working mode, the first valve 4 and the second valve 8 remain open, and the gas-phase component 12 continuously participates in the reaction through the catalyst 7 on the fixed bed 6 in the form of a mobile phase, realizing the ultra-fast capture of catalytic reaction active intermediates, which is suitable for catalytic reactions with relatively high in-situ photocatalytic reaction efficiency;

[0012] In the pulsed injection working mode, the first valve 4 and the second valve 8 remain closed. When the reaction control time is reached, the second valve 8 is opened to realize the rapid direct analysis of the gas-phase component 12 at different stages of the reaction.

[0013] The further technical solution is as follows:

[0014] The working surface of the fixed bed 6 is a smooth plane.

[0015] The material of the sand core 11 is quartz, and the diameter of the sand holes in the sand core 11 is 0.1 - 1 mm; the distance between the sand core 11 and the outer end face of the molecular beam skimmer 10 in the photoionization time-of-flight mass spectrometer is less than 20 mm.

[0016] A water cooling mechanism or an air cooling mechanism is provided on the back of the reaction light source 5 for controlling the photocatalytic reaction temperature.

[0017] The reaction light source 5 is an ultraviolet light source, a visible light source, an infrared light source, or a white light source; the relationship between the number of reaction light sources 5 and the surface area of the fixed bed 6 is 1 reaction light source per 2 square centimeters.

[0018] Powdery catalyst is coated on the inner wall of the hollow closed plate-shaped shell corresponding to the working surface of the fixed bed 6, or catalyst particles with a particle size smaller than the sand holes in the sand core 11 are filled.

[0019] The beneficial technical effects of the present invention are reflected in the following aspects:

[0020] 1. In the present invention, the molecular beam photoionization time-of-flight mass spectrometry can perform near-in-situ sampling on gas-phase intermediates and products in the photocatalytic reactor, and the pressure in the photocatalytic reactor can be adjusted to a vacuum environment, which can promote the desorption of intermediate species adsorbed on the catalyst surface. Due to the ultra-fast sampling rate of the molecular beam mass spectrometry, the reaction intermediates desorbed under low pressure can be transported to the photoionization region within the time range of milliseconds and detected by the time-of-flight mass spectrometry after ionization. For the detection of gas-phase products in conventional catalytic reactions, if separated by gas chromatography and then analyzed by mass spectrometry, it generally requires an analysis time of half an hour or more; even if the gas-phase products of the catalytic reaction are directly transferred into mass spectrometry for analysis, it also requires at least a second-level analysis time. Therefore, the present invention can achieve ultra-fast capture of photocatalytic reaction intermediates.

[0021] 2. Compared with the catalytic reactor used in thermal catalytic in-situ mass spectrometry, the present invention has two beneficial technical effects: First, the in-situ photocatalytic reactor is a fixed-bed structure, and the fixed bed is a flat cuboid structure. This structure increases the irradiation area of the fixed-bed catalyst, avoids the scattering of the excitation light source by the arc surface of the cylindrical reactor in the thermal catalytic reactor, can not only ensure the full contact between the reaction gas and the catalyst, but also make the appropriate thickness of the catalytic reactor match the irradiation depth of the photocatalytic reaction excitation light source; fully utilize the number of photons radiated by the light source, improve the gas-solid phase flow photocatalytic reaction efficiency, increase the content of trace gas-solid phase photocatalytic reaction intermediates, and facilitate the capture of gas-phase reaction intermediates by molecular beam-photoionization time-of-flight mass spectrometry. Second, due to the fast recombination rate of photo-generated electrons and holes of the catalyst and the low photocatalytic reaction efficiency, a first valve for inlet gas and a second valve for outlet gas are respectively arranged on both sides of the fixed bed as needed. For gas-solid phase photocatalytic reactions with different efficiencies, it can be switched between continuous injection mode and pulse injection mode under low pressure or normal pressure.

[0022] 3. The traditional batch photocatalytic reactor is a closed reaction environment, mainly using the natural adsorption of reaction gas and catalyst under normal pressure and then initiating the photocatalytic reaction by the excitation of the reaction light source. Compared with the traditional batch photocatalytic reactor, the present invention has two beneficial technical effects: First, during the flow of the reaction gas, it is in full contact with the catalyst; Second, the gas-phase reaction intermediates on the surface of the catalyst can be introduced into the photoionization chamber of the differential chamber ultrafast photoionization time-of-flight mass spectrometry in the present invention.

[0023] 4. When the synchrotron radiation light source is used as the vacuum ultraviolet ionization source, the present invention can also achieve near-threshold "soft" ionization of complex gas-phase components by adjusting the energy of the synchrotron radiation light. At low energies, high-sensitivity detection of trace gas-phase reaction intermediates can be carried out while avoiding interference from high-ionization-energy reactants. Moreover, by scanning the energy of the synchrotron radiation light, accurate qualitative and quantitative analysis can be performed according to the photoionization efficiency curve, which is very suitable for the characterization of complex gas-solid phase photocatalytic reactions.

[0024] 5. In addition, compared with the most commonly used quadrupole mass spectrometer, the time-of-flight mass spectrometry adopted by the present invention has no mass detection discrimination, and theoretically has no lower and upper limits of mass detection. Moreover, the mass resolution of the quadrupole mass spectrometer is generally only a few hundred, while the reflectron time-of-flight mass analyzer adopted by the present invention has a higher mass resolution.

[0025] 6. The unknown gas-phase molecules to be measured in the present invention can be accurately qualitatively analyzed by the mass-to-charge ratio (m / z) of ions, isotope ratio, ionization energy, and photoionization efficiency curve (PIE). BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a mass spectrometry analysis device for in-situ gas-solid phase photocatalytic reaction.

[0027] Figure 2 It is the mass spectrometry diagram of photocatalytic oxidation of methane at 14.2 eV.

[0028] Figure 3 It is the mass spectrometry diagram of photocatalytic oxidation of methane at 11 eV.

[0029] Figure 1-2 In the figure: the first inlet pipe 1, the second inlet pipe 2, the third inlet pipe 3, the first valve 4, the reaction light source 5, the fixed bed 6, the catalyst 7, the second valve 8, the differential chamber 9, the molecular beam leak spoon 10, the sand core 11, the gas phase components 12, the first pumping port 13, the vacuum ultraviolet light 14, the repulsion electrode 15, the focusing electrode 16, the second pumping port 17, the sampling cone 18, the focusing lens 19, the slit 20, the reflectron time-of-flight mass analyzer 21, the detector 22, the ion flight trajectory 23, the third pumping port 24. Specific implementation manner

[0030] The present invention will be further described below with reference to the accompanying drawings through embodiments. Embodiment

[0031] See Figure 1 , a mass spectrometry analysis device for in-situ gas-solid phase photocatalytic reaction, comprising a photoionization time-of-flight mass spectrometry device and an in-situ photocatalytic reactor, which are connected by a differential chamber 9. The photoionization time-of-flight mass spectrometry device is a reflectron time-of-flight mass spectrometry analysis device. The in-situ photocatalytic reactor includes a catalyst placement mechanism, a reaction light source 5, an inlet pipe and an outlet pipe. The improvement lies in:

[0032] The catalyst placement mechanism includes a flat fixed bed 6 and a hollow closed plate-shaped shell. The material of the fixed bed 6 is quartz. The fixed bed 6 is located inside the plate-shaped shell, and the material of the plate-shaped shell is transparent quartz glass; the material of the fixed bed 6 is quartz. The side surface of the fixed bed 6 where the catalyst is placed is the working surface, and the working surface is a smooth plane. The size of the fixed bed 6 is 18 mm (length) × 18 mm (width) × 3 mm (height). The reaction light source 5 is an ultraviolet light source. The reaction light source 5 is located above the plate-shaped shell, and the light-emitting surface of the reaction light source 5 corresponds to the working surface of the fixed bed 6; the relationship between the number of the reaction light sources 5 and the surface area of the fixed bed 6 is 1 reaction light source 5 per square centimeter. A water cooling mechanism is provided on the back of the reaction light source 5 to control the temperature of the photocatalytic reaction. One end of the inlet pipe communicates with the middle of one side edge in the length direction of the plate-shaped shell, and a first valve 4 is installed on the inlet pipe adjacent to the fixed bed 6; the middle of the other side edge in the length direction of the plate-shaped shell communicates with one end of the outlet pipe, and a second valve 8 is installed on the outlet pipe adjacent to the fixed bed 6; the other end of the outlet pipe is located inside the differential chamber 9, and a sand core 11 is installed in the outlet pipe between the plate-shaped shell and the second valve 8.

[0033] The material of the sand core 11 is quartz, and the diameter of the sand hole in the sand core 11 is 0.5 mm; the distance between the sand core 11 and the outer end surface of the molecular beam colander 10 in the photoionization time-of-flight mass spectrometer is 20 mm.

[0034] See also Figure 1 The reflective time-of-flight mass spectrometer mainly comprises a molecular beam colander 10, a vacuum ultraviolet light source 14, an ion introduction system and a reflective time-of-flight mass spectrometer 21. The ion introduction system comprises a repeller electrode 15, a focusing electrode 16, a sampling cone 18 and a focusing lens 19; wherein the repeller electrode 15, the focusing electrode 16 and the sampling cone 18 are located in a photoionization chamber.

[0035] The time-of-flight mass spectrometer has a resolution of 2000, the vacuum ultraviolet light source is a synchrotron radiation light source (5-24.5 eV continuously adjustable), the surface area of ​​the fixed bed 6 is 1 square centimeter, and a reaction light source 5 is provided. The vacuum of the fixed bed 6 and the differential chamber 9 is 0.2 Torr, and the vacuum of the photoionization chamber is 9×10 -2 Pa, vacuum degree of reflective time-of-flight mass analyzer 9×10 -5 Pa, the reaction light source 5 is a 400W xenon lamp, and 16 sccm nitrogen, 4 sccm oxygen and 2 sccm methane are introduced into the first inlet tube 1, the second inlet tube 2 and the third inlet tube 3 respectively.

[0036] The working mode of this embodiment 1 is a continuous injection working mode, and the working principle is described in detail as follows:

[0037] First, open the first valve 4 and the second valve 8, and the gaseous raw materials, intermediates and measured products enter the inlet pipe through the first inlet pipe 1, the second inlet pipe 2 and the third inlet pipe 3 respectively through the flow meter to adjust the flow rate, enter the plate-shaped shell through the first valve 4, and catalyze the catalyst 7 on the fixed bed 6 under the action of the reaction light source 5 to obtain the gaseous component 12; the reaction light source 5 emits a light beam focused on the surface of the catalyst 7 on the fixed bed 6, improves the photon density per unit area, improves the efficiency of the online photocatalytic reaction, and then increases the concentration of the gaseous reaction intermediate. The gaseous component 12 flows out from the second valve 8 on the outlet pipe, first passes through the sand core 11, and the sand hole structure in the sand core 11 reduces the collision between the gaseous components 12, preventing the quenching of the gaseous reaction intermediate of the photocatalytic reaction. The gas phase component 12 enters the photoionization chamber from the molecular beam sieve 10 through the differential chamber 9, and the stable and unstable gas phase products "frozen" by the molecular beam reach between the repeller plate 15 and the focusing plate 16, and are ionized by the vacuum ultraviolet light 14 vertically introduced into the photoionization chamber. After the gas phase component 12 is ionized, it is vertically introduced into the reflective time-of-flight mass analyzer 21 through the sampling cone 18, the focusing lens 19, and the slit 20 under the action of the electric field, and finally reaches the detector 22 for detection.

[0038] The working modes of the present invention are divided into two types. One is the continuous injection working mode, and the other is the pulse injection working mode. The specific descriptions are as follows:

[0039] Continuous injection working mode: The first valve 4 and the second valve 8 remain open, and the gas participates in the reaction continuously in the form of the mobile phase through the catalyst 7 on the fixed bed 6. The reaction residence time in this mode is short, but it can achieve the ultrafast capture of the catalytic reaction active intermediate, and it is suitable for catalytic reactions with relatively high in-situ photocatalytic reaction efficiency.

[0040] Pulse injection working mode: The first valve 4 and the second valve 8 remain closed. When the reaction control time is reached, the second valve 8 is opened to achieve the rapid and direct analysis of the reaction gas phase components at different stages. This pulse injection working mode is suitable for the mode with relatively low in-situ photocatalytic reaction efficiency. This pulse injection working mode has two advantages: 1. It prolongs the time of the low-pressure in-situ photocatalytic reaction, which can not only retain the gas phase reaction intermediate under low pressure to prevent quenching, but also continuously increase the concentration of the gas phase reaction intermediate to a concentration that can be detected in-situ by extending the time; 2. Since in the reflectron time-of-flight mass spectrometry analysis device, a vacuum degree of the photoionization chamber higher than 1 Pa will seriously affect the ion transmission efficiency. In the continuous injection working mode, in order not to affect the normal operation of the mass spectrometry, the vacuum degree of the photoionization chamber cannot be too high. However, in the pulse injection working mode, the pressure of the photoionization chamber can be appropriately increased to increase the concentration of the gas phase reactants, and then increase the concentration of the gas phase intermediates and products, which is convenient for providing more molecules for detection.

[0041] In this embodiment, taking the methane oxidation reaction as an example, the catalyst is 0.1 wt% Ag / ZnO, and the reaction equation is CH4 + O2 → CO2 + H2O. The experimental conditions are as above, and then the mass spectrometry diagrams are collected at 14.2 eV ( Figure 2 ) and 11 eV ( Figure 3 ) for 300 s. As Figure 2 , first, when the photon energy is adjusted to 14.2 eV, in addition to the reactants CH4 (m / z 16) and O2 (m / z 32), there are also signals of the products CO2 (m / z 44) and H2O (m / z 18), indicating that the reaction occurs smoothly on the fixed bed reactor of the present invention. However, since the ion signal generated by the ionization of the reaction gas is too strong, it will suppress the signal of the low-abundance compounds. Therefore, the photon energy is reduced from 14.2 eV to 11 eV. At this time, as Figure 3, CH4, O2, CO2, and H2O cannot be ionized. Trace amounts of reactive intermediates such as methyl radicals (CH3▪, m / z 15), formaldehyde (HCHO, m / z 30), and ethylene (C2H4, m / z 28.03) desorb from the catalyst surface at low pressure and are then successfully detected. Moreover, due to the absence of high-intensity signal suppression by the reaction gas, there is an extremely small amount of air in the vacuum photoionization chamber, and ammonia (NH3, m / z 17) in the air can also be detected.

[0042] Those skilled in the art can easily understand that the above embodiments are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A mass spectrometry analysis device for in-situ gas-solid phase photocatalytic reaction, comprising a photoionization time-of-flight mass spectrometry device and an in-situ photocatalytic reactor, which are connected by a differential chamber (9); the photoionization time-of-flight mass spectrometry device is a reflective time-of-flight mass spectrometry analysis device; the in-situ photocatalytic reactor includes a catalyst placement mechanism, a reaction light source (5), an inlet pipe, and an outlet pipe; characterized in that: The catalyst placement mechanism includes a flat fixed bed (6) and a hollow closed plate-shaped housing. The material of the fixed bed (6) is quartz, and the fixed bed (6) is located inside the plate-shaped housing. The material of the plate-shaped housing is quartz glass; the material of the fixed bed (6) is quartz, and the side of the fixed bed (6) where the catalyst is placed is the working surface; the reaction light source (5) is located above the plate-shaped housing, and the light-emitting surface of the reaction light source (5) corresponds to the working surface of the fixed bed (6); one end of the inlet pipe is connected to the middle of one side edge in the length direction of the plate-shaped housing, and a first valve (4) is provided on the inlet pipe adjacent to the fixed bed (6); one end of the outlet pipe is connected to the middle of the other side edge in the length direction of the plate-shaped housing, and a second valve (8) is provided on the outlet pipe adjacent to the fixed bed (6); the other end of the outlet pipe is located inside the differential chamber (9), and a sintered core (11) is provided in the outlet pipe between the plate-shaped housing and the second valve (8); the working surface of the fixed bed (6) is a smooth plane; the material of the sintered core (11) is quartz, and the diameter of the sand holes in the sintered core (11) is 0.1 - 1 mm; the distance between the sintered core (11) and the outer end surface of the molecular beam skimmer (10) in the photoionization time-of-flight mass spectrometry device is less than 20 mm; During operation, the vacuum degrees in the plate-shaped housing and the differential chamber (9) are the same, ranging from 0.1 Torr to atmospheric pressure; In the continuous sampling operation mode, the first valve (4) and the second valve (8) remain open, and the gas-phase components (12) continuously participate in the reaction through the catalyst (7) on the fixed bed (6) in the form of a mobile phase, realizing the ultrafast capture of catalytic reaction active intermediates, which is suitable for catalytic reactions with relatively high in-situ photocatalytic reaction efficiency; In the pulsed sampling operation mode, the first valve (4) and the second valve (8) remain closed. When the reaction control time is reached, the second valve (8) is opened to realize the rapid direct analysis of the gas-phase components (12) in different reaction stages.

2. The mass spectrometry analysis device for in-situ gas-solid phase photocatalytic reaction according to claim 1, wherein: A water cooling mechanism or an air cooling mechanism is provided on the back of the reaction light source (5) to control the photocatalytic reaction temperature.

3. The mass spectrometry analysis device for in-situ gas-solid phase photocatalytic reaction according to claim 1, wherein: The reaction light source (5) is an ultraviolet light source, a visible light source, an infrared light source, or a white light source; the relationship between the number of reaction light sources (5) and the surface area of the fixed bed (6) is 1 reaction light source (5) per square centimeter.

4. The mass spectrometry analysis device for in-situ gas-solid phase photocatalytic reaction according to claim 1, characterized in that: Powdery catalyst is coated on the inner wall of the hollow closed plate-shaped housing corresponding to the working surface of the fixed bed (6), or catalyst particles with a particle size smaller than the sand holes in the sintered core (11) are filled.

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